微波消解-ICP-AES法同时测定茶叶中微量元素

[目的]采用微波消解样品,等离子体发射光谱(ICPAES)法同时测定茶叶中Fe、Cu、Zn3种元素在实际工作中的实用意义。[方法]微波消解ICPAES法同时测定茶叶中微量元素与国标法测定铁、铜、锌进行比较。[结果]微波消解ICPAES法与国标法测定铁、铜、锌比较,结果无显著性差异(P>0.05)。[结论]用微波消解ICPAES法同时测定茶叶中的铁、铜、锌的结果能够与国标法同样满足实验室检测要求,且检测结果准确度高、精密度好。     

Simulation of the θ′ Precipitation Process with Interfacial Anisotropy Effects in Al-Cu Alloys

The effects of anisotropic interfacial properties and heterogeneous elasticity on the growth and ripening of plate-like θ′-phase (Al₂Cu) in Al-1.69 at.% Cu alloy are studied. Multi-phase-field simulations are conducted and discussed in comparison with aging experiments. The precipitate/matrix interface is considered to be anisotropic in terms of its energy and mobility. We find that the additional incorporation of an anisotropic interfacial mobility in conjunction with the elastic anisotropy result in substantially larger aspect ratios of the precipitates closer to the experimental observations. The anisotropy of the interfacial energy shows comparably small effect on the precipitate’s aspect ratio but changes the interface’s shape at the rim. The effect of the chemo-mechanical coupling, i.e., the composition dependence of the elastic constants, is studied as well. We show that the inverse ripening phenomenon, recently evidenced for δ’ precipitates in Al-Li alloys (Park et al. Sci. Rep. 2019, 9, 3981), does not establish for the θ′ precipitates. This is because of the anisotropic stress fields built around the θ′ precipitates, stemming from the precipitate’s shape and the interaction among different variants of the θ′ precipitate, that disturb the chemo-mechanical effects. These results show that the chemo-mechanical effects on the precipitation ripening strongly depend on the degree of sphericity and elastic isotropy of the precipitate and matrix phases.     

Effects of Transfection with the Cu,Zn-Superoxide Dismutase Gene on Xanthine/Xanthine Oxidase-Induced Cytotoxicity in Fibroblasts from Rat Skin

Purpose. The effects of transfection with the human Cu, Zn-superoxide dismutase (hSOD)⁴ gene on active oxygen-induced cytotoxicity in rat skin fibroblasts (FR) were studied for the purpose of developing the novel delivery system of hSOD using hSOD gene. Methods. An expression plasmid for hSOD, pRc/RSV-SOD, was constructed and used to transfect FR cells. Xanthine (X)/xanthine oxidase (XO) system were used to generate active oxygen species. The effects of transfection with the hSOD gene on active oxygen-induced cytotoxicity were assessed by comparing the number of surviving cells and the level of lipid peroxidation in host and transformants after exposure to X/XO system. Results. The cellular SOD activity in RSV-SOD cells transfected with pRc/RSV-SOD was significantly increased in comparison with host or RSV cells transfected with the pRc/RSV plasmid containing no hSOD gene as a control. Furthermore, Western blot analysis using an anti-hSOD antibody indicated the production of hSOD in RSV-SOD cells. On the other hand, although the numbers of surviving cells in both host and RSV-SOD cultures after exposure to X/XO system decreased in a time-dependent manner, the decrease in number of surviving RSV-SOD cells was less than that in host cells. In the presence of catalase, the decreases in number of surviving cells in both host and RSV-SOD cultures after exposure to the X/XO system were also less than those in the absence of catalase. However, the decreases in cell survival in RSV-SOD cultures were significantly less than those in host cells in the presence of catalase. Furthermore, the levels of lipid peroxidation in RSV-SOD cells exposed to the X/XO system in the presence or absence of catalase were lower than those in host cells. These results indicated that the increase in cellular SOD activity by transfection with the hSOD gene protects cells from oxidative stress. Conclusions. Human SOD gene therapy may be useful for treatment of diseases in which oxidative tissue damage is produced.     

二硫代氨基甲酸吡咯烷诱导人肝癌细胞凋亡的铜离子依赖性机制

目的：测定二硫代氨基甲酸吡咯烷（PDTC）处理对人肝癌细胞Hep3B凋亡的诱导作用及Cu^2 对这种作用的影响。方法：运用细胞增殖力、膜损伤、DNA片断化、细胞周期DNA含量测定分析PDTC对人肝癌细胞株Hep3B细胞的增殖抑制及凋亡诱导作用及Cu^2 在其中发挥的作用。结果：PDTC处理后，细胞增殖能力显著下降。乳酸脱氢酶（LDH）分析显示细胞膜并没有被破坏，DNA凝胶电泳及细胞周期DNA含量测定发现明显的凋亡特征性DNA片断及亚G1峰，显示细胞增殖能力的降低源于细胞凋亡的发生。低浓度Cu^2 显著加强了PDTC的细胞增殖抑制及凋亡诱导作用，而Cu^2 络合剂Bathocuproine disulfonate(BCS)显著抑制PDTC的两种作用。结论：PDTC铜离子依赖性地抑制人肝癌细胞增殖并诱导细胞凋亡。     

红细胞铜锌超氧化物歧化酶与血清维生素C在糖尿病肾病时的变化

目的：探讨氧化与抗氧化在糖尿病肾病发生发展中的作用。方法：测定对照（Ｃ）组１５人及糖尿病蛋白尿正常（ＤＭⅠ）组、微量白蛋白尿（ＤＭⅡ）组、临床蛋白尿（ＤＭⅢ）组患者共５６例的红细胞铜，锌超氧化物歧化酶（ＳＯＤ）及血清维生素（ＶｉｔＣ）。结果：ＳＯＤ与尿白蛋白排泄率（ＵＡＥＲ）呈明显负相关，ＤＭⅡ组明显高于Ｃ、ＤＭⅠ组，低于ＤＭⅢ组（Ｐ＜０．０１）；ＶｉｔＣ与ＵＡＥＲ呈明显负相关（Ｐ＜０．０１），但ＤＭⅠ与Ⅱ组，ＤＭⅡ、Ⅲ组间Ｐ＞０．０５；ＳＯＤ、ＶｉｔＣ与ＨｂＡ１Ｃ间呈负相关，前者Ｐ＜０．０１，后者Ｐ＞０．０５。结论：抗氧化能力下降可能是糖尿病发生肾脏损伤的原因之一，并可反映损伤程度。     

正常儿童超氧化物歧化酶检测

作者用双抗体夹心法测定了711例正常儿童血Cu、Zn-SOD含量,结果显示随年龄增长体内Cu、Zn-SOD含量逐渐升高。     

克汀病病区胎儿血及组织中Cu,Zn含量及CuZnSOD活性观察

测定地方性克汀病病区引产胎儿血及肝、脑组织中Ｃｕ、Ｚｎ含量及ＣｕＺｎＳＯＤ活性，同时孕妇血相应指标。发现病区胎儿及孕妇血以及胎儿肝、脑组织中Ｚｎ含量、ＣｕＺｎＳＯＤ活性均低于非病区，而Ｃｕ含量病区与非病区比较无明显差异，表明病区胎儿存在锌营养不足及由此引起的抗化功能下降。病区胎儿的这处代谢紊乱可能与碘缺乏因素等共同构成克汀病发病的基础。     

孕妇及新生儿血清硒,铜,锌的含量关系

测定56例非孕妇和66例不同孕期妇女及30例新生儿(脐血)血清中硒、铜、锌三种微量元素。结果表明,孕妇血清硒锌随孕期进展明显低于非孕妇,而孕晚期血清铜显著升高;新生儿血清硒、锌显著高于母血水平,铜低于母血。     

β-环糊精修饰超氧化物歧化酶的代谢动力学研究

牛血铜，锌-超氧化物歧化酶（Cu，Zn－SOD）用高碘酸钠活化的β-环糊精（β-Cyclodextrin，β-CD）修饰。对修饰酶静脉注射兔体进行药代动力学研究，结果表明β－CD修饰的SOD在兔体内基本符合二室模型，其特征方程为C＝236e－7.0937t＋60e-0.4473t，修饰SOD的T为0．11±0．04h和1．66±0．48h，体内CLB为53±11．10L／（kg·h），曲线下面积AUC为176．5±35．40U（L·h）。